EP 0896151 A3 20000322 - Synthetic low friction piston for a hydraulic pump or motor
Title (en)
Synthetic low friction piston for a hydraulic pump or motor
Title (de)
Reibungsarmer Kunststoffkolben für hydraulische Pumpen oder Motoren
Title (fr)
Piston en matériau synthéthique à basse friction pour une pompe ou un moteur hydraulique
Publication
Application
Priority
JP 21188897 A 19970806
Abstract (en)
[origin: EP0896151A2] A hydraulic pump or motor comprises a rotating disk member (31) supported free to rotate in a housing (11), and a cylinder block (14) supported free to rotate in the space of the housing (11) around a rotation axis inclined to the rotation axis of the rotating disk member (31). The rotating disk member (31) and cylinder block (14) are connected by a joint (17), and they are rotated in the same way by a drive shaft (12). A hemispherical shoe (29) in contact with the rotating disk member (31) via a spherical surface and having a smooth surface (29A) on the other side, comes in contact with a pad (27) of synthetic resin attached to the tip of a piston (20). The pad (27) has a smooth support surface (27A) perpendicular to the piston axis, and comes in contact with the smooth surface (29A) of the shoe (29) on this support surface (27A). A pocket (27D) for leading a cylinder internal pressure through the piston is formed on the contact surface between the pad (27) and shoe (29) forming a hydrostatic bearing. Each of the pistons (20) is pushed in the extending direction by a spring (21). A cylindrical piston cap (23) formed of a low friction synthetic resin on the outer circumference of the piston (20) slides in a cylinder bore (18). <IMAGE>
IPC 1-7
IPC 8 full level
CPC (source: EP US)
F04B 1/124 (2013.01 - EP US); F05C 2225/00 (2013.01 - EP US)
Citation (search report)
- [A] WO 9602756 A1 19960201 - DANFOSS AS [DK], et al
- [A] WO 9602752 A1 19960201 - DANFOSS AS [DK], et al
- [A] GB 1136634 A 19681211 - BENNES MARREL
- [A] US 3175510 A 19650330 - D AMATO MICHAEL A
- [A] EP 0728945 A1 19960828 - BRUENINGHAUS HYDROMATIK GMBH [DE]
Designated contracting state (EPC)
AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE
DOCDB simple family (publication)
EP 0896151 A2 19990210; EP 0896151 A3 20000322; EP 0896151 B1 20030625; DE 69815766 D1 20030731; DE 69815766 T2 20040506; DK 0896151 T3 20031020; JP 3703610 B2 20051005; JP H1150950 A 19990223; US 6092457 A 20000725
DOCDB simple family (application)
EP 98306172 A 19980803; DE 69815766 T 19980803; DK 98306172 T 19980803; JP 21188897 A 19970806; US 12903898 A 19980804